In South Korea, curved designs are catching on. This time it’s the batteries for smartphones.

LG Chem’s cable-shaped battery and curved battery are seen in this undated photograph.

LG Chem

LG Electronics Inc.’s battery making affiliate, LG Chem Ltd. said it has started mass-producing “curved” batteries this month that will eventually be used for LG’s upcoming smartphone, which will have a curved screen.

It didn’t disclose details on the battery life in its announcement this week.

As absurd as the race toward curved designs may seem, LG’s not alone in the pursuit of such forms for smartphone components.

Earlier this year, Samsung Group’s battery making unit Samsung SDI Co. said slightly curved batteries would be available for smartphone makers by the second half of this year.

Back then, the understanding was that these batteries would be used for fancy smartwatches that would be curved to fit a person’s wrist. But with smartwatches like Sony Corp.’s SmartWatch 2 and Samsung Electronics Co.’s Galaxy Gear looking more like traditional watches with big, flat screens, the need for curved batteries had been fizzling out.

Samsung Electronics then made a surprise announcement last month saying it would soon introduce a curved-screen smartphone. It wasn’t immediately clear whether this phone would need a curved battery.

Analysts have cast doubts over the potential sales value of these curved phones, saying that customers will have a hard time finding a good reason for buying them.

But both Samsung and LG would argue that they’re moving closer to making wearable, flexible mobile devices.

LG also said this week that it has developed batteries shaped like cable wires, which can be bended and wrapped around devices easily. The company said these batteries could be used for wearable devices shaped like necklaces, but added that it would take years to start mass-production of the batteries.